The Radiation Therapy Committee (RTC) is composed of all radiation therapists in primary institutions of the Childrens Cancer Study Group (CCSG). Radiotherapists from affiliate institutions, who hold appointments to CCSG Study Committees, are also members. RTC members attend Group Meetings and vote on scientific and administrative matters related to Group activities, especially those affecting radiation. Memmbers of the RTC are expected to coordinate CCSG-related activities with radiotherapists in affiliated institutions. A Radiation Executive Committee is composed of those who hold CCSG Committee assignments. The Steering Committee advises the Group Chairman and the CCSG Executive Committee (EC) on radiation related affairs. The RTC exists in order to coordinate radiation activities throughout the network or radiation therapists in CCSG and to insure a scientific concensus of these radiation therapists in all CCSG protocols. The RTC insures inclusion of radiation in all CCSG protocols when this modality is of therapeutic necessity and/or scientific interest. Exclusion of radiation in CCSG protocols requires RTC guidance and approval. Scientific results of CCSG studies are monitored and reviewed by the RTC at all Group Meetings (and by interim mail) and modifications necessary in ongoing studies are made as applicable. RTC leaderhsip embraces representation on most CCSG study committees (on all which include delivery of radiation) and includes Chairmanship of certain major CCSG Study Committees, Strategy Groups and Standing Committees. Achievements in pediatric radiation oncology to date include: study and refinement of radiation for CNS prophylaxis in ALL: the first Cooperative Group to introduce total body irradiation into Group studies of AML, failed ALL and neuroblastoma (Stage IV); retrospective evaluation of dose response for non-Hodgkin's lymphoma; the first Cooperative Group to study radiation sensitizers in children (brain tumors). Leadership in Intergroup studies have resulted in advances in using and refining radiation in these diseases. National symposia under CCSG sponsorship has provided valuable communications and monograph publications to radiotherapists generally. Future plans involve and expansion of these efforts in all of these areas.